Wyniki wyszukiwania - Biblioteka Nauki

1

R&D of ECR ion sources: news and perspectives

100%

Gammino S.

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tom Vol. 48,suppl.2

73-79

EN

The future accelerators need ion beams with higher charge state and higher current. This demand will be met by the “third generation Electron Cyclotron Resonance Ion Sources” (ECRIS) which will make use of improved plasma confinement by means of higher magnetic field and of higher microwave frequency, thus boosting the performance of nowadays ECRIS operating at the frequency of 14 and 18 GHz. The possibility to obtain confining fields exceeding 4 tesla, by means of special design of NbTi superconducting magnets, open the way to a new operational domain, at the typical frequencies of gyrotrons, above 28 GHz, with plasma densities never achieved before in ECRIS (1013 cm–3 and higher). The test of SERSE at 28 GHz, confirming the theoretical frame on which the third generation ECR sources design is based, will be presented; a synthetic review of the new generation ECRIS is carried out, with a particular emphasis on the design of the GyroSERSE source. Finally, the scheme of an innovative hybrid source will be outlined and a short description of the ECLISSE (Electron Cyclotron Resonance ion source Coupled to a Laser Ion Source for charge State Enhancement) experiment is hereinafter presented.

2

The TSL 6.4 GHz ECR ion source – status, improvements and measurements

80%

van Rooyen D. , Wessman D.

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tom Vol. 48,suppl.2

99-104

EN

The TSL 6.4 GHz ECR ion source performs reliably and is well optimized for the various ion species that are routinely provided for experiments. Beam intensities are comparable with other similar sources but at the lower end of the spectrum. We are thus investigating a number of methods of improvement. The development of a micro-oven for low melting point materials was successfully concluded. Further development is needed to improve the consumption rate in order to enable more effective use of expensive isotopes. Measurements with operation of the source in the after-glow mode were successful but the pulse to pulse reproducibility should be further improved. Although the maximum gain compared to the CW mode is satisfactory, accomplishing a higher factor would be even more advantageous for beams delivered to CELSIUS. A systematic study of various parameters was started in order to find optimal operating conditions running in the after-glow mode

3

Physical Characteristics of the Modified Glow Discharge Ion Source

80%

Soliman B. , Abdelrahman M. , Basal N. , Abdelsalam F.

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nr 1

10-14

EN

This work is concerned with a study on the operating characteristics of a self-axial extraction-type glow-discharge ion source. This compact ion source, with conical anode of various divergence angle Θ, can work under different operating conditions. An output ion beam currents I_{b} were measured at a distance d_{cc} = 5 cm from the plane cathode, and were found to be dependent upon the gas pressure p, angle Θ and the discharge current I_{d}. High ion beam currents of 85 μA and 410 μA were obtained at the optimum angle Θ=30° for discharges: [N₂ gas, p = 2.9×10¯² mbar, I_{d} = 2 mA] and [H₂ gas, p = 7.7×10¯² mbar, I_{d} = 2 mA], respectively.

4

Recent development in ECR sources

60%

Bieth C. , Kantas S. , Sortais P. , Kanjilal D. , Rodrigues G.

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tom Vol. 48,suppl.2

93-98

EN

Recent developments and improvements on the ECR ion source family at PANTECHNIK S.A. are presented. A lot of work has been done in the Ion Implantation Technology with the MICROGAN IndustryŽ source: more than 3 mA have been produced on B1+, P1+ and few hundred žAe on charge state 3+, 4+. Three other developments are described in this paper: a) the construction of the first source using high temperature superconducting coils (30 K) PKSUSŽ - Space Cryomagnetics (UK), in collaboration with NSC (New Delhi); b) the construction of the PHOENIX ECR source (used in the “1+/n+” process for radioactive beam) for different laboratories; c) and the first results on PK 2.45 (a cheap source working at 2.45 GHz) able to produce high current of monocharged beam. We will also present some special products for beam acceleration and diagnosis.

5

Status of the Warsaw ECR ion source and injection line

60%

Sudlitz K. , Kulczycka E. , Filipiak B. , Górecki A.

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tom Vol. 48,suppl.2

105-108

EN

A room temperature home built 10 GHz ECR ion source delivers beams of B, C, N, O, F, Ne, S, Ar to the Cyclotron U200-P. The same ion source has also been used for surface irradiation of the solids. To upgrade the ion source and increase the ion current in the cyclotron an oven for evaporation of solid materials has been constructed and a two gap buncher has been installed in the injection line. Some new observations on the influence of the extraction system on the ion beam current will be presented.

6

Źródło jonów dla potrzeb spektroskopii jądrowej wykorzystujące plazmę generowaną strumieniem elektronów

60%

Turek M. , Maczka D. , Słowiński B. , Yushkevich Y. , Pyszniak K. , Zubrzycki J.

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2013

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tom R. 89, nr 5

290-293

PL

Zaprezentowano konstrukcję źródła jonów z plazmą generowaną strumieniem elektronów a także omówiono warunki pracy w reżymach on-line i off-line. Zaletą źródła jest jego dość duża wydajność (rzędu 2-5 % dla pierwiastków trudnolotnych) osiągana dzięki powstaniu pułapki potencjału w komorze jonizacyjnej. Przedstawiono oszacowania krytycznych warunków pracy zapewniających powstanie tej pułapki, a także optymalnej temperatury roboczej katody oraz ograniczenia narzucane przez konstrukcję źródła na okresy półrozpadu jonizowanych nuklidów.

EN

Construction of the electron beam generated plasma ion source is presented as well as its working conditions in the on-line and off-line modes. The advantage of the source is its relatively high ionization efficiency (~2-5% for refractory metals) achieved due to the existence of the potential trap inside the ionization chamber. The estimations of the critical working parameters leading to the formation of the trap and the estimation of the optimal cathode temperature are given. The constraints imposed by the construction details on ionized nuclide half-life are discussed.

7

Charakteryzacja diod p-i-n wytworzonych metodą implantacji warstw epitaksialnych 4H-SiC jonami glinu

41%

Kwietniewski N. , Pazio K. , Sochacki M. , Szmidt J. , Droździel A. , Kulik M. , Prucnal S. , Pyszniak K. , Rawski M. , Turek M. , Żuk J.

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2009

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tom Vol. 50, nr 6

32-35

PL

W pracy opisano wytwarzanie i charakteryzację diod p-i-n wytwarzanych w strukturach epitaksjalnych 4H-SiC. W celu uzyskania warstw typu p⁺ wykonano 4-krotną implantację jonami Al przy całkowitej dawce 7,1 · 10¹⁴ cm⁻2² dla uzyskania prostokątnego rozkładu głębokościowego. Implantację prowadzono przy temperaturze tarczy 500°C z użyciem implanatora jonów UNIMAS wyposażonego w plazmowe źródło jonów naszej konstrukcji. Zaimplantowany materiał został następnie wygrzany w argonie przez 20 min. w t = 1600°C. Przeprowadzono badania rozkładów głębokościowych SIMS oraz rozpraszania mikro-ramanowskiego. Z pomiarów metodą c-TLM wyznaczono wartości rezystancji charakterystycznej kontaktów. Pomiary Halla wykazały, że koncentracja nośników w warstwie implantowanej p⁺ o grubości 350 nm zawiera się w przedziale 3...4 · 10¹⁸ cm⁻³ Gęstość prądu wytworzonych diod osiąga maksymalną wartość 220 A/cm² przy polaryzacji w kierunku przewodzenia 10 V, natomiast napięcie przebicia zawiera się w granicach 550...600 V.

EN

We report on fabrication and characterization of 4H-SiC p-i-n diodes. In order to obtain p⁺ -type layer, a four energy Al box-like profile was implanted with atotal fluence of 7,1 • 10 ¹¹ cm ⁻² at 500°C, using the UNIMAS ion implanter equipped with a plasma ion source of our construction. Implanted material was subsequently annealed for 20 min at 1600°C in argon. SIMS depth profiling and micro-Raman scattering investigations we re performed. The values of specific contact resistance were determined by the c-TLM method. The performed Hall measurements have shown that 350 nm thick p⁺ layers are characterized by carrier concentration of 3...4 • 10 ¹⁸ cm ⁻³. The fabricated diodes have probed forward current density up to 220 A/cm² at 10 V forward drop and 550...600 V breakdown voltages.